Finding the Fourth Proportional to 111.57, 153.90 and 72.28

Step by Step Solution

1. Step 1: Write the proportion equation
   111.57 : 153.90 = 72.28 : x
2. Step 2: Convert to fraction form
   111.57/153.90 = 72.28/x
3. Step 3: Cross multiply
   111.57x = 153.90 × 72.28
4. Step 4: Simplify right side
   111.57x = 11,123.89
5. Step 5: Solve for x
   x = 11,123.89/111.57
6. Step 6: Final answer
   x = 99.70